Latch



R. CALPIN 1,821,879

Sept. 1, 1931.

LATCH Filed March 4. 1927 Vai Patented Sept. 1, 19,31

UNITED STATES PATENT OFFICE RAYMOND CALIIN, F EVERETT, MASSACHUSETTS,ASSIGNOR TO A. S.' CAMPBELL COMPANY, OF EAST BOSTON, MASSACHUSETTS, ACORPORATION OF MASSACHUSETTS LATCH Application mea March 4,

This invention relates to latching devices for doors and the like andthe object is to provide mechanism of this type which will readily4catch and firmly hold the door but which may be easily unlatclud.Although not limited thereto, the construction finds particularapplication to the doors of automobiles.

My invention will be readily understood by reference to the followingdescription of an illustrative embodiment thereof taken in connectionwith the accompanying drawings, whereinz. Fig. 1 is a horizontal sectionthrough the x lock side ofan automobile door and its cooperating jamb,showing the latch mechanism in section at substantially the plane of thebolt;

Fig. 2 is an. elevation of the latch casing detached disclosing theinterior mechanism;

Fig. 3 is a section on the line 3-3 of Fig. 2; and l Figs. 4 and 5 aresections at the crack of the door and looking toward the jamb showingthe amb fitting or keeper in elevation, the cover plate being omitted,and illustrating respectively the latching positionv of the parts andthe position at the moment of unlatching. y

Referring to the drawings, the latching mechanism comprises as usual apart carried by the door 7 and a. cooperating fitting or keeper whichisattached to the cooperating door jamb 9. The former may be organized ona suitable latch plate or casing having a portion 11 overlying theinner' face of the door and a fiange portion 13 extending over the-edgethereof. Through the Harige 13 projects the bolt which herein takes theof the invention shown this pinion is cradled in a rigid lug 17projecting ,from the plate 13 in which it rotates under suitablecontrol, as hereinafter tobe described; The jamb fitting, shown indetail in Figs. 4 and 5, is open toward the outer 'side of the door toreceive the lug and the projecting pinion as the door swings towardclosed position and is herein shown as embodying a-rigid form of apinion 15 and in the embodiment surface 19 adapted'to underride andsupport 192,7. Serial No. 172,812.

the lug 17 and an overhanging rack 21 here- 1n shown as pivoted at 23 atits forward end and spring-pressed downwardly by spring 25 into the pathof the pinion 15 so thatas the door swings closed and the pinion 55moves from the dotted line position of Fig. 4 to the full line positionit rolls into engagementwith the rack, compressing spring 25 andswinging the rack from the position of Fig. 5 to that of Fig. 4. In thisaction the 30 surface 19 underrides'the lug 17, raising the doorsomewhat as indicated in Fig. 4 if the door sags, and rigidly supportsthe latched door in such position, the latch thus serving the functionof the socalled dovetail commonly installed on automobile doors. Thepinion 15 is in this manner brought to proper elevation accurately toengage the rack 21. The mechanism of.- the jamb fittmg or keeper may beenclosed in a suitable case 27 and the interior mechanism shown in Figs4 and 5 is enclosed by a suitable cover plate 28 notV shown in thosefigures but appearing in Fig. 1 attached by means of 9suitable screwtapping into the opening 75 The pinion is permitted to roll freely in acounter-clockwise direction, viewing Fig. 4, and suitablev means areprovided to prevent, at least normally, reverse rotation of the 30pinion such as would be required to permit it to roll out of engagementwith the rack from the position of Fig. 4.' I have herein shown(see Fig.3) a ratchet wheel 31 located at the inner side of the plate 13, beingsecured thereagainst by the lugs 33. The wheel 31 may be broachedout toreceive the teeth -of the pinion 15 so that it is supported o-nthe-latter as on a shaft and with a splined connection thereto, by whichterm I mean to include such a connection as will cause two members torotate one with the other while permitting sliding movement, thissliding ymovement taking place axially of the pinion for a purpose whichwill hereinafter appear. Cooperating with the ratchet wheel 31 is asuitable pawl which herein takes the form of a sprin 35 secured to the'plate 11. As the door c oses and the pinion rolls into the rack, theteeth ofthe ratchet click over the pawl. A position of the pinion isprovided for each tooth on the ratchet wheel, and it will be seen thatif the teeth of the pinion and those of the rack are once engaged, the

door is latched even if not pushed to its full closed position. Thearrangement, therefore, provides for holding the door latched in amultiplicity of closed positions as distinguished from the customarybolt which provides ordinarily a single closed position or only tworelatively widely spaced positions in those cases where a stepped keeperis provided.

To unlatch the door after it is latched in the positions of Fig. 1 andFig'. 4 the pinion and rack may be separated by a relative movementthereof axially of the pinion without disturbing the locking of theratchet wheel 31 and herein the pinion 15 is retracted through the wheel3l. I have herein shown a slide 37 mounted on an embossed portion 39 ofthe plate 11 and sliding under the gibs or lugs 41 parallel to the axialline of the pinion, the slide being provided with an angular-lyextending arm 43 riveted at 45 to the inner end of the pinion bolt. Theslide may be normally pressed toward the left, viewing Figs. 1 and 2, bymeans of a suitable spring 47 to project the pinion to the full ineposition of Fig. 2 and any suitable means may be provided to draw theslide to the right to retract the same to the dotted line position and Ihave herein shown by way of example an arm 49 projecting upwardly fromthe slide and adapted to cooperate with a roll-back 51 on the handlespindle 53. The door being closed and the parts in the position of Fig.4, if the slide 37 is then operated, the pinion 15 is withdrawn from therack and the /door may be freely opened. The position of the parts inthe jamb fitting is then as shown in Fig. 5.

In Figs. 4 and 5 I have illustrated a suitl able kick-out spring 55secured to the back of the jamb fitting casing 27 and adapted to beengaged by the lug 17 and compressed by the same as it moves to the fullline position of Fig. 4. When the inion is retracted. as shown in Fig.5. lie lug 17 renains in contact with the spring 55, the latter expandsand, acting against the lug, tends to open the door and to carry the lugout to the dotted line position of Fig. 4 Where the retracted pinion, ifallowed again to project. will not come into engagement with the rack.

It will be seen that in the preferred embodiment of the invention shownthe mechanism which prevents reverse rotation of the pinion isconstantly' in action. That is, the pawl 35 is always in engagement withratchet wheel 31 and it thus may be made strong and durable. Theretraction of the bolt out of engagement with the rack permits the doorto be opened easily and readily without any dificulty such as might becaused by a binding of the parts due to some disalignment or inaccuracyin installation. Such disalignment would not be material in the closingmovement of the door because the door is swung to and is moving withconsiderable momentum but might offer diiculties in startin the dooropen from the closed position. t the same time an easy engagement of thedoor in latched position in provided for without the necessity of anysnap action as in the ordinary sliding spring projecting bolt, and afterthe teeth of the pinion have once engaged the `rack the door is heldagainst opening and may be so held in a practically unlimited series ofclosed positions. There is practically no danger of swinging the door towithout its being caught and held.

I have thus described in detail the particular embodiment of myinvention shown by way of example in the accompanying drawings. It willbe understood that the particularity of this description has had for itsobject making clear the construction and operation of the particularform of my invention here shown and that the principles exemplifiedthereby are by no means limited in their embodiment to what has beenillustrated. What I claim as new and desire to secure by Letters PatentI shall express in the following claims.

1. In a latch a bolt adapted to project from the edge of the door, akeeper constructed to engage the projected bolt and to interlocktherewith by rotation of the latter consequent on such engagement, meansto prevent reverse rotation of the projected bolt and means to retractsubstantially in the direction of the axis of rotation the bolt to freeit from said keeper.

2. In alatch mechanism a latch member having a rigid lng projectingtherefrom, a bolt supported on and slidable on the lug, a jamb fittinghaving asurface to underride and rigidly support the lug and a partoverhanging t e projecting bolt, means permitting free relative movementof the projecting bolt and said part in the closing movement of the doorbut preventing such movement in the opposite-direction, and meansslidably to retract the bolt tofree it from the fitting.

3. In a latch mechanism a latch member having a rigid lug projectingtherefrom, a bolt supported on and slidable on the lug, a jamb fittinghaving a surface to underride and rigidly support the lug and a partoverhanging the projecting bolt, means permitting free relative movementol` the projecting bolt and said part in the closing movement of thedoor but preventing such movement in the opposite direction, meansslidably to retract the bolt to free it from the titloe members, meansto prevent the reverse rotation of the pinion in one direction andproviding for latching together of the members in a multiplicity ofpositions of closed adjustment, and means for separating the rack andpinion subsantially axially of the latter to' unlatch the members. v

5. In a mechanism for latching together two members a bolt whichprovides a pinion projecting from one member, a. rack on the other`member into which the pinion mayroll, a member having splinedconnection with said bolt, means cooperating with said last named memberto permit its rotation in one direction only, and means to retract thebolt by sliding movement thereof through said member to withdraw saidpinion laterally from the rack. A

6. In a latch mechanism for doors a plate at the door edge having a lugprojecting therefrom, a pinion cradled in the lug and extending throughthe plate, a member at the inner side of the plate slidably fitting theteeth of the pinion, mea-ns controlling the rotation of said member andImeans slidably to `retract the pinion, and a cooperating jamb littingcomprising a surface to underride and support the lug and an overhangingtoothed memberto mesh with the pinion in its projected position.

7. In a latch mechanism a latch member havin a rigid lug projectingtherefrom, a rotata le bolt sliding on said lug, a jamb fitting having asurface to underride and rigidly support the lug and a partoverhanglng-the-projected bolt and adapted to interengage therewith byrotation thereof consequent on closing movement, means to preventreverse rotation of the bolt, and means slidably to retract the bolt tofree it from its fitting.

8. In a latch for a @or and its case a bolt which provides arotatable`pn`ion, the axis of which is positioned to project axiallyfrom the edge of one of the members to which the latch is applied tocross the joint between them, a cooperating rack into which the pinionmay roll when the door closes, means to Lprevent reverse rotation of thepinion and means effective while the door remains closed to move thepinion bodily out of mesh with the rack to release the latch.

and groove connection of the bolt with said part, means cooperating withsaid lastnamed part to permit its rotation in one direction only, andmeans to retract the bolt by sliding vmovement thereof throu h said partto withdraw said pinion lateral y from the rack.

In testimony whereof, I have signed m name to this'specificationl IRAYMOND CALPIN.

9.' In a mechanism for latching together two members a bolt whichaffords a pinion projecting from one member, arack on the other memberinto which the pinion may roll, a part associated with said first memberthrough which the pinion extends, the teeth of the latter providing a sliding tongue

